The present invention relates to a fastening device, and more particularly to a fastening device with non reversible slide-on heads.
Devices for securing one article to another that allow non-reversible insertion of a ridged shaft or the like into a locking device, such as xe2x80x9ctie-wrapsxe2x80x9d are known. For example, as shown in FIG. 1, flexible variable-length fasteners 12 with one molded on head 14 and one slide-on head 16 are known. These fasteners 12 are commonly used to install, for example, aftermarket fluid/oil coolers to the front or rear surface of an automotive radiator. The shaft portion 18 of the fastener is small enough in outside diameter to allow insertion through the core of a typical automotive radiator, between cooling fins and tubes. The shaft portion 18 includes ridges, knobs or other locking members 20 that control movement of the slide-on head 16 directionally, allowing installation and advancing movement onto the shaft portion 18, but preventing withdrawal.
When securing a cooler to the front surface of a radiator using the fastener 12, installation is accomplished as follows: The auxiliary cooler is placed in the desired mounting position, against the surface of the radiator. The shaft portion 18 of the fastener 12 is inserted through the cooler and the radiator core until the molded on head 14 comes into contact with the cooler and a portion of the shaft 18 extends out the back side of the radiator. The slide-on head 16, which includes an opening 22 defined therethrough, is then installed onto the shaft portion 18 that is protruding through the back side of the radiator and advanced over the knobs 20 to the point of contact with the radiator, thereby securing the cooler to the radiator (typically a plurality of fasteners 12 are used).
Very often though, fastener 12 installation is complicated by accessories, such as the fan, fan shroud, coolant hoses, belts, etc., which limit access to the area behind the radiator, because once the slide-on head 16 is placed onto the shaft portion 18 it is difficult to advance the slide-on head 16 all the way to where it is in contact with the radiator.
There are other prior art devices that include a flexible shaft portion including ridges or knobs for non-reversible directional control. However, in many of these fasteners, the flexible shaft portion is inserted into a portion that is already secured to the shaft (such as the aforementioned xe2x80x9ctie-wrapxe2x80x9d), thereby forming a loop. For example, U.S. Pat. No. 5,117,575 to Desmond teaches a fastener that has oppositely facing conically shaped knob-sections that are flexible. The fastener has a locking device disposed on the shaft and between the two knob-sections. The opposite ends of the shaft are inserted into the locking device, thereby forming a loop. This type of fastener can not be used in some situations, such as the example above of securing a cooler to a radiator.
A long felt need exists for a fastening device that does not form a loop, is easy to install, and overcomes the other disadvantages of the prior art.
In accordance with a first aspect of the present invention there is provided a fastening device including a shaft portion having first and second sections and opposite ends and at least two slide-on heads each having an opening defined therethrough and being adapted to engage the first and second sections respectively. The slide-on heads are adapted to only move inwardly with respect to the opposite ends of the shaft portion. In a preferred embodiment, the first and second sections each include a plurality of axially aligned, outwardly oriented locking members. The locking members of the second section are oriented oppositely of the locking members of the first section. In another preferred embodiment, the shaft portion includes an intermediate section disposed between the first and second sections that has a dimension along its transverse axis. The opening of the slide-on heads has a width. The dimension of the intermediate section is larger than the width (dependent on geometric shape; diameter, width, etc.) of the openings.
In accordance with another aspect of the present invention there is provided a fastening device that includes a shaft portion having at least first and second opposed sections and at least two slide-on heads. The first and second sections include a discontinuous surface, whereby when the slide-on heads are placed on the shaft portion the slide-on heads can be moved readily towards each other and less readily away from each other. In a preferred embodiment, the discontinuous surface is formed by locking members that are either conically shaped or saw tooth shaped.
In accordance with yet another aspect of the present invention there is provided a method of securing a first object to a second object using a fastening device. The method includes the steps of positioning the first object adjacent the second object, installing a first slide-on head at the end of a second section of a shaft portion of the fastening device, inserting a first section of a shaft portion of the fastening device through a front side of the first and second objects such that the first section protrudes from a back side of the second object and the first slide-on head contacts the front side of the first object, installing a second slide-on head onto the first section, and then advancing the first slide-on head further onto the second section, thereby holding the first and second objects in secure contact. In a preferred embodiment, the method also includes the step of pulling a portion of the shaft portion back through the first and second objects before advancing the slide-on head onto the second section.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.